In-depth security news and investigation

Posts Tagged: target data breach

The malicious software that unknown thieves used to steal credit and debit card numbers in the data breach at Home Depot this year was installed mainly on payment systems in the self-checkout lanes at retail stores, according to sources close to the investigation. The finding could mean thieves stole far fewer cards during the almost five-month breach than they might have otherwise.

A self-checkout lane at a Home Depot in N. Virginia.

Since news of the Home Depot breach first broke on Sept. 2, this publication has been in constant contact with multiple financial institutions that are closely monitoring daily alerts from Visa and MasterCard for reports about new batches of accounts that the card associations believe were compromised in the break-in. Many banks have been bracing for a financial hit that is much bigger than the exposure caused by the breach at Target, which lasted only three weeks and exposed 40 million cards.

But so far, banking sources say Visa and MasterCard have been reporting far fewer compromised cards than expected given the length of the Home Depot exposure.

Sources now tell KrebsOnSecurity that in a conference call with financial institutions today, officials at MasterCard shared several updates from the ongoing forensic investigation into the breach at the nationwide home improvement store chain. The card brand reportedly told banks that at this time it is believed that only self-checkout terminals were impacted in the breach, but stressed that the investigation is far from complete. Continue reading →

The apparent credit and debit card breach uncovered last week at Home Depot was aided in part by a new variant of the malicious software program that stole card account data from cash registers at Target last December, according to sources close to the investigation.

Photo: Nicholas Eckhart

On Tuesday, KrebsOnSecurity broke the news that Home Depot was working with law enforcement to investigate “unusual activity” after multiple banks said they’d traced a pattern of card fraud back to debit and credit cards that had all been used at Home Depot locations since May of this year.

A source close to the investigation told this author that an analysis revealed at least some of Home Depot’s store registers had been infected with a new variant of “BlackPOS” (a.k.a. “Kaptoxa”), a malware strain designed to siphon data from cards when they are swiped at infected point-of-sale systems running Microsoft Windows.

The information on the malware adds another indicator that those responsible for the as-yet unconfirmed breach at Home Depot also were involved in the December 2013 attack on Target that exposed 40 million customer debit and credit card accounts. BlackPOS also was found on point-of-sale systems at Target last year. What’s more, cards apparently stolen from Home Depot shoppers first turned up for sale on Rescator[dot]cc, the same underground cybercrime shop that sold millions of cards stolen in the Target attack.

Clues buried within this newer version of BlackPOS support the theory put forth by multiple banks that the Home Depot breach may involve compromised store transactions going back at least several months. In addition, the cybercrime shop Rescator over the past few days pushed out nine more large batches of stolen cards onto his shop, all under the same “American Sanctions” label assigned to the first two batches of cards that originally tipped off banks to a pattern of card fraud that traced back to Home Depot. Likewise, the cards lifted from Target were sold in several dozen batches released over a period of three months on Rescator’s shop.

The cybercrime shop Rescator[dot]cc pushed out nine new batches of cards from the same “American Sanctions” base of cards that banks traced back to Home Depot.

POWERFUL ENEMIES

The tip from a source about BlackPOS infections found at Home Depot comes amid reports from several security firms about the discovery of a new version of BlackPOS. On Aug. 29, Trend Micro published a blog post stating that it had identified a brand new variant of BlackPOS in the wild that was targeting retail accounts. Trend said the updated version, which it first spotted on Aug. 22, sports a few notable new features, including an enhanced capability to capture card data from the physical memory of infected point-of-sale devices. Trend said the new version also has a feature that disguises the malware as a component of the antivirus product running on the system.

Contents of the new BlackPOS component responsible for exfiltrating stolen cards from the network. Source: Trend Micro.

Evidence that a major U.S. retailer had been hacked and was leaking card data first surfaced Tuesday on the cybercrime store rescator[dot]cc, the shop that was principally responsible for selling cards stolen in the Target, Sally Beauty, P.F. Chang’s and Harbor Freight credit card breaches.

As with cards put up for sale in the wake of those breaches, Rescator’s shop lists each card according to the city, state and ZIP code of the store from which each card was stolen. See this story for examples of this dynamic in the case of Sally Beauty, and this piece that features the same analysis on the stolen card data from the Target breach.

Stolen credit cards for sale on Rescator’s site index each card by the city, state and ZIP of the retail store from which each card was stolen.

The ZIP code data allows crooks who buy these cards to create counterfeit copies of the credit and debit cards, and use them to buy gift cards and high-priced merchandise from big box retail stores. This information is extremely valuable to the crooks who are purchasing the stolen cards, for one simple reason: Banks will often block in-store card transactions on purchases that occur outside of the legitimate cardholder’s geographic region (particularly in the wake of a major breach).

Thus, experienced crooks prefer to purchase cards that were stolen from stores near them, because they know that using the cards for fraudulent purchases in the same geographic area as the legitimate cardholder is less likely to trigger alerts about suspicious transactions — alerts that could render the stolen card data worthless for the thieves.

This morning, KrebsOnSecurity pulled down all of the unique ZIP codes in the card data currently for sale from the two batches of cards that at least four banks have now mapped back to previous transactions at Home Depot. KrebsOnSecurity also obtained a commercial marketing list showing the location and ZIP code of every Home Depot store across the country.

Here’s the kicker: A comparison of the ZIP code data between the unique ZIPs represented on Rescator’s site, and those of the Home Depot stores shows a staggering 99.4 percent overlap.

Home Depot has not yet said for certain whether it has in fact experienced a store-wide card breach; rather, the most that the company is saying so far is that it is investigating “unusual activity” and that it is working with law enforcement on an investigation. Here is the page that Home Depot has set up for further notices about this investigation.

I double checked the data with several sources, including with Nicholas Weaver, a researcher at the International Computer Science Institute (ICSI) and at the University California, Berkeley. Weaver said the data suggests a very strong correlation.

“A 99+ percent overlap in ZIP codes strongly suggests that this source is from Home Depot,” Weaver said.Continue reading →

Multiple banks say they are seeing evidence that Home Depot stores may be the source of a massive new batch of stolen credit and debit cards that went on sale this morning in the cybercrime underground. Home Depot says that it is working with banks and law enforcement agencies to investigate reports of suspicious activity.

Contacted by this reporter about information shared from several financial institutions, Home Depot spokesperson Paula Drake confirmed that the company is investigating.

“I can confirm we are looking into some unusual activity and we are working with our banking partners and law enforcement to investigate,” Drake said, reading from a prepared statement. “Protecting our customers’ information is something we take extremely seriously, and we are aggressively gathering facts at this point while working to protect customers. If we confirm that a breach has occurred, we will make sure customers are notified immediately. Right now, for security reasons, it would be inappropriate for us to speculate further – but we will provide further information as soon as possible.”

There are signs that the perpetrators of this apparent breach may be the same group of Russian and Ukrainian hackers responsible for the data breaches at Target, Sally Beauty and P.F. Chang’s, among others. The banks contacted by this reporter all purchased their customers’ cards from the same underground store — rescator[dot]cc — which on Sept. 2 moved two massive new batches of stolen cards onto the market.

A massive new batch of cards labeled “American Sanctions” and “European Sanctions” went on sale Tuesday, Sept. 2, 2014.

In what can only be interpreted as intended retribution for U.S. and European sanctions against Russia for its aggressive actions in Ukraine, this crime shop has named its newest batch of cards “American Sanctions.” Stolen cards issued by European banks that were used in compromised US store locations are being sold under a new batch of cards labled “European Sanctions.” Continue reading →

News that Target’s CEO Gregg Steinhafle is stepping down has prompted a flurry of reports from media outlets trying to recap events since the company announced a data breach on Dec. 19, 2013. Sprinkled throughout those reports were lots of numbers, which got me to thinking about synthesizing them with some of the less-reported numbers associated with this epic breach.

40 million– The number of credit and debit cards thieves stole from Target between Nov. 27 and Dec. 15, 2013.

70 million – The number of records stolen that included the name, address, email address and phone number of Target shoppers.

200 million – Estimated dollar cost to credit unions and community banks for reissuing 21.8 million cards — about half of the total stolen in the Target breach.

100 million – The number of dollars Target says it will spend upgrading their payment terminals to support Chip-and-PIN enabled cards.

0 – The number of customer cards that Chip-and-PIN-enabled terminals would have been able to stop the bad guys from stealing had Target put the technology in place prior to the breach (without end-to-end encryption of card data, the card numbers and expiration dates can still be stolen and used in online transactions).

0 – The number of people in Chief Information Security Officer (CISO) or Chief Security Officer (CSO) jobs at Target (according to the AP).

Last week’s story about steeply falling prices on credit and debit card data stolen from Target mentioned several reasons why many banks may not have already reissued all of their cards impacted by the breach. But it left out one other key reason: A huge backlog of orders at companies that manufacture credit and debit cards on behalf of financial institutions.

Turns out, while the crooks responsible for monetizing the Target breach seem to have had little trouble counterfeiting stolen cards, the process by which banks obtain legitimate replacement cards for their customers is not always quite so speedy.

I recently spoke with a gentleman who heads up security at a small federal credit union, and this individual said his institution ended up printing their own cards in-house after being told by their financial services provider that their order for some 2,000 new customer cards compromised in the Target breach would have to get behind a backlog of more than 2 million existing orders from other banks.

The credit union in question issues Visa-branded cards to its customers, but the actual physical cards are produced by Fiserv, a Brookfield, Wisc. financial services firm that also handles the online banking portals for a huge number of small to mid-sized financial institutions nationwide. In addition to servicing this credit union, Fiserv also prints cards for some of the biggest banks in the world, including Bank of America and Chase.

Shortly after the holidays, the credit union began alerting affected customers, notifying them that the institution would soon be reissuing cards. But when it actually went to place the order for the new cards, the institution was told it would have to get in line.

“They informed us that there was a backlog of 2 million cards, and said basically, ‘We’ll get to you when we get to you’,” the credit union source told KrebsOnSecurity.

Murray Walton, chief risk officer at Fiserv, acknowledged that the company has experienced extraordinarily high demand for new cards in the wake of the Target breach, but that Fiserv is quickly whittling down its existing backlog of orders.

“A large breach injects additional demand into a system that is already operating at near-peak capacity at year-end,” Walton said. “As a result, producers face the challenge of juggling existing contractual commitments with this incremental demand, and turn to mandatory overtime and staff augmentation to get the most out of their equipment and infrastructure. We believe we are managing this situation as well as possible, and are beginning to see our cycle times (order to delivery) diminish compared to a few weeks ago. Meanwhile, we note that fraud prevention is a multi-faceted challenge, and card reissue is only one arrow in the quiver. Alert consumers and behind-the-scenes fraud management programs are also essential.”

Faced with mounting customer service requests from account holders who’d been told to expect new cards, the credit union decided to take matters into its own hands.

“We have the capability to print out the cards ourselves at a local branch, so some of our software developers wrote some scripts to export the customer data and we had two people who ended up burning the midnight oil for several days making these cards by hand.”

Last year’s breach at Target Corp. flooded underground markets with millions of stolen credit and debit cards. In the days surrounding the breach disclosure, the cards carried unusually high price tags — in large part because few banks had gotten around to canceling any of them yet. Today, two months after the breach, the number of unsold stolen cards that haven’t been cancelled by issuing banks is rapidly shrinking, forcing the miscreants behind this historic heist to unload huge volumes of cards onto underground markets and at cut-rate prices.

Cards stolen in the Target breach have become much cheaper as more of them come back declined or cancelled by issuing banks.

Earlier today, the underground card shop Rescator[dot]so moved at least 2.8 million cards stolen from U.S.-based shoppers during the Target breach. This chunk of cards, dubbed “Beaver Cage” by Rescator, was the latest of dozens of batches of cards stolen from Target that have gone on sale at the shop since early December.

The Beaver Cage batch of cards have fallen in price by as much as 70 percent compared to those in “Tortuga,” a huge chunk of several million cards stolen from Target that sold for between $26.60 and $44.80 apiece in the days leading up to Dec. 19 — the day that Target acknowledged a breach. Today, those same cards are now retailing for prices ranging from $8 to $28. The oldest batches of cards stolen in the Target breach –i.e., the first batches of stolen cards sold –are at the top of legend in the graphic above; the “newer,” albeit less fresh, batches are at the bottom.

The core reason for the price drop appears to be the falling “valid rate” associated with each batch. Cards in the Tortuga base were advertised as “100 percent valid,” meaning that customers who bought ten cards from the store could expect all 10 to work when they went to use them at retailers to purchase high-priced electronics, gift cards and other items that can be quickly resold for cash.

This latest batch of Beaver Cage cards, however, carries only a 60 percent valid rate, meaning that on average customers can expect at least 4 out of every 10 cards they buy to come back declined or canceled by the issuing bank.

The most previous batch of Beaver Cage cards — pushed out by Rescator on Feb. 6 — included nearly 4 million cards stolen from Target and carried a 65 percent valid rate. Prior to Beaver Cage, the Target cards were code-named “Eagle Claw.” On Jan. 29, Rescator debuted 4 million cards bearing the Eagle Claw name and a 70 percent valid rate. The first two batches of Eagle Claw-branded cards — a chunk of 2 million cards — were released on Jan. 21 with a reported 83 percent valid rate.

The breach at Target Corp. that exposed credit card and personal data on more than 110 million consumers appears to have begun with a malware-laced email phishing attack sent to employees at an HVAC firm that did business with the nationwide retailer, according to sources close to the investigation.

Last week, KrebsOnSecurity reported that investigators believe the source of the Target intrusion traces back to network credentials that Target had issued to Fazio Mechanical, a heating, air conditioning and refrigeration firm in Sharpsburg, Pa. Multiple sources close to the investigation now tell this reporter that those credentials were stolen in an email malware attack at Fazio that began at least two months before thieves started stealing card data from thousands of Target cash registers.

Two of those sources said the malware in question was Citadel — a password-stealing bot program that is a derivative of the ZeuS banking trojan — but that information could not be confirmed. Through a PR firm, Fazio declined to answer direct questions for this story, and Target has declined to comment, citing an active investigation.

In a statement (PDF) issued last week, Fazio said it was “the victim of a sophisticated cyber attack operation,” and further that “our IT system and security measures are in full compliance with industry practices.”

There is no question that, like Target, Fazio Mechanical was the victim of cybercrime. But investigators close to the case took issue with Fazio’s claim that it was in full compliance with industry practices, and offered another explanation of why it took the Fazio so long to detect the email malware infection: The company’s primary method of detecting malicious software on its internal systems was the free version of Malwarebytes Anti-Malware.

To be clear, Malwarebytes Anti-Malware (MBAM) free is quite good at what it’s designed to do – scan for and eliminate threats from host machines. However, there are two problems with an organization relying solely on the free version of MBAM for anti-malware protection: Firstly, the free version is an on-demand scanner that does not offer real-time protection against threats (the Pro version of MBAM does include a real-time protection component). Secondly, the free version is made explicitly for individual users and its license prohibits corporate use.

Fazio’s statement also clarified that its data connection to Target was exclusively for electronic billing, contract submission and project management. The company did not specify which component(s) of Target’s online operations that Fazio accessed externally, but a former employee at Target said nearly all Target contractors access an external billing system called Ariba, as well as a Target project management and contract submissions portal called Partners Online. The source said Fazio also would have had access to Target’s Property Development Zone portal.

According to a former member of Target’s security team who asked not to be identified, when a work order for an external vendor is created, the payment is collected through the Ariba system: Vendors log into Ariba, complete the necessary steps to close out the work order and they are later paid. But how would the attackers have moved from Target’s external billing system into an internal portion of the network occupied by point-of-sale devices? The former Target network expert has a theory:

“I know that the Ariba system has a back end that Target administrators use to maintain the system and provide vendors with login credentials, [and] I would have to speculate that once a vendor logs into the portal they have active access to the server that runs the application,” the source said. “Most, if not almost all, internal applications at Target used Active Directory (AD) credentials and I’m sure the Ariba system was no exception. I wouldn’t say the vendor had AD credentials but that the internal administrators would use their AD login to access the system from inside. This would mean the sever had access to the rest of the corporate network in some form or another.”

Last week’s story about Fazio’s role in the attack on Target mentioned that Target could be facing steep fines if it was discovered that the company was not in compliance with payment card industry (PCI) security standards. Among those is a requirement that merchants incorporate two-factor authentication for remote network access originating from outside the network by personnel and all third parties.

Another source who managed Target vendors for a number of years until quite recently said that only “in rare cases” would Target have required a vendor to use a one-time token or other two-factor authentication approach.

“Only the vendors in the highest security group — those required to directly access confidential information — would be given a token, and instructions on how to access that portion of the network,” the source said, speaking on condition of anonymity. “Target would have paid very little attention to vendors like Fazio, and I would be surprised if there was ever even a basic security assessment done of those types of vendors by Target.”

But according to Avivah Litan, a fraud analyst at Gartner, Target wouldn’t have needed to require vendors to use two-factor logins if the company believed it had taken steps to isolate the vendor portals from its payment network.

“In fairness to Target, if they thought their network was properly segmented, they wouldn’t have needed to have two-factor access for everyone,” Litan said. “But if someone got in there and somehow escalated their Active Directory privileges like you described, that might have [bridged] that segmentation.”

OPEN-SOURCE INTEL

Many readers have questioned why the attackers would have picked on an HVAC firm as a conduit for hacking Target. The answer is that they probably didn’t, at least at first. Many of these email malware attacks start with shotgun attacks that blast out email far and wide; only after the attackers have had time to comb through the victim list for interesting targets do they begin to separate the wheat from the chaff.

But Target may have inadvertently made it easier for the attackers in this case, in part by leaving massive amounts of internal documentation for vendors on its various public-facing Web properties that do not require a login. Indeed, many of these documents would be a potential gold mine of information for an attacker.

Last week, Target told reporters at The Wall Street Journal and Reuters that the initial intrusion into its systems was traced back to network credentials that were stolen from a third party vendor. Sources now tell KrebsOnSecurity that the vendor in question was a refrigeration, heating and air conditioning subcontractor that has worked at a number of locations at Target and other top retailers.

Sources close to the investigation said the attackers first broke into the retailer’s network on Nov. 15, 2013 using network credentials stolen from Fazio Mechanical Services, a Sharpsburg, Penn.-based provider of refrigeration and HVAC systems.

Fazio president Ross Fazio confirmed that the U.S. Secret Service visited his company’s offices in connection with the Target investigation, but said he was not present when the visit occurred. Fazio Vice President Daniel Mitsch declined to answer questions about the visit. According to the company’s homepage, Fazio Mechanical also has done refrigeration and HVAC projects for specific Trader Joe’s, Whole Foods and BJ’s Wholesale Club locations in Pennsylvania, Maryland, Ohio, Virginia and West Virginia.

Target spokeswoman Molly Snyder said the company had no additional information to share, citing a “very active and ongoing investigation.”

It’s not immediately clear why Target would have given an HVAC company external network access, or why that access would not be cordoned off from Target’s payment system network. But according to a cybersecurity expert at a large retailer who asked not to be named because he did not have permission to speak on the record, it is common for large retail operations to have a team that routinely monitors energy consumption and temperatures in stores to save on costs (particularly at night) and to alert store managers if temperatures in the stores fluctuate outside of an acceptable range that could prevent customers from shopping at the store.

“To support this solution, vendors need to be able to remote into the system in order to do maintenance (updates, patches, etc.) or to troubleshoot glitches and connectivity issues with the software,” the source said. “This feeds into the topic of cost savings, with so many solutions in a given organization. And to save on head count, it is sometimes beneficial to allow a vendor to support versus train or hire extra people.”

An examination of the malware used in the Target breach suggests that the attackers may have had help from a poorly secured feature built into a widely-used IT management software product that was running on the retailer’s internal network.

As I noted in Jan. 15’s story — A First Look at the Target Intrusion, Malware — the attackers were able to infect Target’s point-of-sale registers with a malware strain that stole credit and debit card data. The intruders also set up a control server within Target’s internal network that served as a central repository for data hoovered up from all of the infected registers.

“ttcopscli3acs” is the name of the Windows share used by the POS malware planted at Target stores; the username that malware used to upload stolen card data was “Best1_user”; the password was “BackupU$r”

That analysis looked at a malware component used in Target breach that was uploaded to Symantec’s ThreatExpert scanning service on Dec. 18 but which was later deleted (a local PDF copy of it is here). The ThreatExpert writeup suggests that the malware was responsible for moving stolen data from the compromised cash registers to that shared central repository, which had the internal address of 10.116.240.31. The “ttcopscli3acs” bit is the Windows domain name used on Target’s network. The user account “Best1_user” and password “BackupU$r” were used to log in to the shared drive (indicated by the “S:” under the “Resource Type” heading in the image above.

That “Best1_user” account name seems an odd one for the attackers to have picked at random, but there is a better explanation: That username is the same one that gets installed with an IT management software suite called Performance Assurance for Microsoft Servers. This product, according to its maker — Houston, Texas base BMC Software — includes administrator-level user account called “Best1_user.”

This knowledge base article (PDF) published by BMC explains the Best1_user account is installed by the software to do routine tasks. That article states that while the Best1_user account is essentially a “system” or “administrator” level account on the host machine, customers shouldn’t concern themselves with this account because “it is not a member of any group (not even the ‘users’ group) and therefore can’t be used to login to the system.”

“The only privilege that the account is granted is the ability to run as a batch job,” the document states, indicating that it could be used to run programs if invoked from a command prompt. Here’s my favorite part:

“Perform Technical Support does not have the password to this account and this password has not be released by Perform Development. Knowing the password to the account should not be important as you cannot log into the machine using this account. The password is known internally and used internally by the Perform agent to assume the identity of the “Best1_user” account.”

I pinged BMC to find out if perhaps the password supplied in the Target malware (BackupU$r) is in fact the secret password for the Best1_user account. The company has so far remained silent on this question.

This was the hunch put forward by the Counter Threat Unit (CTU) of DellSecureWorks in an analysis that was privately released to some of the company’s clients this week.

“Attackers exfiltrate data by creating a mount point for a remote file share and copying the data stored by the memory-scraping component to that share,” the SecureWorks paper notes. “In the previous listing showing the data’s move to an internal server, 10.116.240.31 is the intermediate server selected by attackers, and CTU researchers believe the “ttcopscli3acs” string is the Windows domain name used on Target’s network. The Best1_user account appears to be associated with the Performance Assurance component of BMC Software’s Patrol product. According to BMC’s documentation, this account is normally restricted, but the attackers may have usurped control to facilitate lateral movement within the network.”

According to SecureWorks, one component of the malware installed itself as a service called “BladeLogic,” a service name no doubt designed to mimic another BMC product called BMC BladeLogic Automation Suite. BMC spokeswoman Ann Duhon said that the attackers were simply invoking BMC’s trademark to make the malicious program appear legitimate to the casual observer, but it seems likely that at least some BMC software was running inside of Target’s network, and that the attackers were well aware of it.

Update Jan. 30, 5:48 p.m.: BMC just issued the following statement:

There have been several articles in the press speculating about the Target breach. BMC Software has received no information from Target or the investigators regarding the breach. In some of those articles, BMC products were mentioned in two different ways.

The first was a mention of a “bladelogic.exe” reference in the attack. The executable name “bladelogic.exe” does not exist in any piece of legitimate BMC software. McAfee has issued a security advisory stating that: “The reference to “bladelogic” is a method of obfuscation. The malware does not compromise, or integrate with, any BMC products in any way.

The second reference was to a password that was possibly utilized as part of the attack, with the implication that it was a BMC password. BMC has confirmed that the password mentioned in the press is not a BMC-generated password.

At this point, there is nothing to suggest that BMC BladeLogic or BMC Performance Assurance has a security flaw or was compromised as part of this attack.

Malware is a problem for all IT environments. BMC asks all of our customers to be diligent in ensuring that their environments are secure and protected.

I parse their statement to mean that the “BackupU$r” password referenced in the Target malware is not their software’s secret password. But nothing in the statement seems to rule out the possibility that the attackers leveraged a domain user account installed by BMC software to help exfiltrate card data from Target’s network.

Original story:

According to a trusted source who uses mostly open-source data to keep tabs on the software and hardware used in various retail environments, BMC’s software is in use at many major retail and grocery chains across the country, including Kroger, Safeway, Home Depot, Sam’s Club and The Vons Companies, among many others.

A copy of the SecureWorks report is here (PDF). It contains some fairly detailed analysis of this and other portions of the malware used in the Target intrusion. What it states up front that it does not have — and what we still have not heard from Target — is how the attackers broke in to begin with….